Justification of Red List category
This Sulawesi endemic has a relatively large range, within which it is suspected to be undergoing a slow population decline due to ongoing loss and degradation of its forest habitat. Currently this rate of decline does not approach the thresholds for listing as threatened, but this should continue to be closely monitored, with forests on Sulawesi increasingly under pressure from settlements and large-scale logging operations. Presently, the species is considered Least Concern.
Population justification
The population size has not been quantified. It is described as scarce by Eaton et al. (2021) and citizen science data (eBird 2023) appear to support this suggestion, although it is likely to have relatively low detectability. It is noted that the area of forest within its mapped range is large (30,000 km2) and therefore it is unlikely to have an especially small population size, even if only a small proportion of the range is occupied.
Trend justification
Forest loss, degradation and fragmentation are considered the main threats to this species. In the 15 years to 2022, forest cover in the species' range declined by c.10% (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein). The rate of forest loss appears to be increasing (Voigt et al. 2021)—the reduction in tree cover over the next three generations is suspected to be c.13%, based on the rate of loss since 2014 (Global Forest Watch 2023). The species appears largely confined to closed-canopy primary forest (Mauro and Drijvers 2000, Eaton et al. 2021), therefore such rates of deforestation are suspected to be driving declines of 10-19% over three generations.
Tyto inexspectata is endemic to Sulawesi, Indonesia. Its distribution is poorly studied—there are multiple records from North Sulawesi and some from Lore Lindu National Park, Central Sulawesi (Mauro and Drijvers 2000, eBird 2023), but the southern limit of its range is essentially unknown. It was not, for example, detected in South-East Sulawesi by Berryman and Eaton (2020), where it might have reasonably been expected.
It inhabits closed-canopy primary lowland, foothill and lower montane forests from 100-1,800 m (Mauro and Drijvers 2000, Eaton et al. 2021). In more open areas and forest edge, it is replaced by Tyto rosenbergii (Eaton et al. 2021). It is presumably sedentary.
The loss, degradation and fragmentation of forests pose the major threat to the species, principally caused by land clearance for settlements, agricultural and infrastructural development and large-scale logging. High-quality, lowland forests have been the most impacted throughout (Voigt et al. 2021). This species also occurs at higher altitudes, buffering overall decline rates from the worst of forest loss, but ongoing threats are still thought to be causing significant declines which, when combined, may be driving population reductions equivalent to 10-19% over three generations.
Conservation Actions Underway
CITES Appendix II. It is known to occur in several National Parks, including Tangkoko, Bogani Nani Wartabone and Lore Lindu (eBird 2023).
30 cm. Medium-small, forest-dwelling owl. Light rusty facial disk. Rusty upperparts speckled black, rusty-cream underparts spotted black, wings barred black and rufous. Finely barred tail. Nuchal area and bend of wing darker than rest of plumage. Black iris. Similar spp. Sulawesi Masked-owl T. rosenbergi is much larger, with dusky facial disc and upperparts finely spotted white. There are two morphs of this species, of which the darker is most difficult to differentiate from T. rosenbergi. Voice Single nasal, hoarse, hissing shriek lasting about 1.8 seconds and delivered infrequently every 5-7 minutes (Mauro and Drijvers 2000).
Text account compilers
Berryman, A., Haskell, L.
Contributors
Bishop, K.D. & Verbelen, F.
Recommended citation
BirdLife International (2024) Species factsheet: Minahasa Masked-owl Tyto inexspectata. Downloaded from
https://datazone.birdlife.org/species/factsheet/minahasa-masked-owl-tyto-inexspectata on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.